Atanasov, Mihail Comba, Peter Daul, Claude 2008-02-27 Magnetic anisotropy in cyanide-bridged single-molecule magnets (SMMs) with Fe^III−CN−M^II (M = Cu, Ni) exchange-coupled pairs was analyzed using a density functional theory (DFT)-based ligand field model. A pronounced magnetic anisotropy due to exchange was found for linear Fe^III−CN−M^II units with fourfold symmetry. This results from spin–orbit coupling of the [Fe^III(CN)₆]³⁻ unit and was found to be enhanced by a tetragonal field, leading to a ²E_g ground state for Fe^III. In contrast, a trigonal field (e.g., due to τ_2g Jahn–Teller angular distortions) led to a reduction of the magnetic anisotropy. A large enhancement of the anisotropy was found for the Fe^III−CN−Ni^II exchange pair if anisotropic exchange combined with a negative zero-field splitting energy of the <i>S</i> = 1 ground state of Ni^II in tetragonally compressed octahedra, while cancellation of the two anisotropic contributions was predicted for tetragonal elongations. A recently developed DFT approach to Jahn–Teller activity in low-spin hexacyanometalates was used to address the influence of dynamic Jahn–Teller coupling on the magnetic anisotropy. Spin Hamiltonian parameters derived for linear Fe−M subunits were combined using a vector-coupling scheme to yield the spin Hamiltonian for the entire spin cluster. The magnetic properties of published oligonuclear transition-metal complexes with ferromagnetic ground states are discussed qualitatively, and predictive concepts for a systematic search of cyanide-based SMM materials are presented. application/pdf https://folia.unifr.ch/global/documents/300753 https://folia.unifr.ch/documents/300753/files/daul_clf.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1021/ic701702x info:eu-repo/semantics/openAccess License undefined Inorganic Chemistry. - 2008, vol. 47, no. 7, p. 2449–2463 info:eu-repo/classification/udc/54 Combined ligand field and density functional theory analysis of the magnetic anisotropy in oligonuclear complexes based on Fe^III−CN−M^II exchange-coupled pairs http://purl.org/coar/resource_type/c_6501